<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>条件注释</title>
    <!--[if IE 8]>
    <script>
        alert('哈哈');
    </script>
    此条件注释只对IE浏览器有用
    <!endif]-->
</head>
<body>
踮起脚尖，提起裙边
</body>
</html>